Flow control of fluidized material

ABSTRACT

This apparatus controls the flow of fluidized granular material by utilizing the pressure in the conduit to actuate one valve to increase the supply of gas to the conduit and another valve to restrict the flow of material in the conduit. Any increase in the amount of material will increase the pressure and add more gas and reduce the flow of material into the conduit to maintain continuous flow of fluidized material. When used in a rockdusting system, the fluidized material is discharged from a nozzle at the end of the conduit under control of a manually actuated valve. Closing the valve causes pressure in the conduit closure of the valve restricting flow of the material. The air supply to the conduit will be increased and the supply of material reduced with decrease in the discharge of material at the nozzle.

limited States Patent 1 3,s99,sa2

[72] Inventor Carlowen Smith [56] References Cited A IN 5:53am UNITEDSTATES PATENTS Dec 1969 3,163,329 12/1964 Mornas 222/193x 3,372,9583/1968 Black 222/193x [45] Patented Aug. 17, 1971 [73] AssigneeIndustrial Pneumatic Systems, Inc. Primary Examiner-Stanley H. TollbergFairmont, W. Va. Att0rneyRevere B. Gurley ABSTRACT: This apparatuscontrols the flow of fluidized granular material by utilizing thepressure in the conduit to actuate one valve to increase the supply ofgas to the conduit and another valve to restrict the flow of material inthe conduit. Any increase in the amount of material will increase thepressure and add more gas and reduce the flow of material into theconduit to maintain continuous flow of fluidized material.

When used in a rockdusting system, the fluidized material is dischargedfrom a nozzle at the end of the conduit under con- [54] FLOW CONTROL OFFLUIDIZED MATERIAL 9 Claims, 5 Drawing Figs.

[52] US. Cl 222/1, trol of a manually actuated valve. Closing the valvecauses 222/57, 302/35 pressure in the conduit closure of the valverestricting flow of [51] Int. Cl B67b 7/00 the material. The air supplyto the conduit will be increased [50] Field of Search 302/17, 24, andthe supply of material reduced with decrease in th 35, 42, 36; 222/193,195, 55, 57 discharge ofmaterial at the nozzle.

COMPRESSOR PATENTEU AUG] 71971 3, 599.832

sum 1 OF 2 F/GTI COMPRESSOR INVEN'IOIR CARLOWEN SMITH ATTORNEY PATENTEDAUG] 7 l9?! SHEET 2 OF 2 INVENTOR CARLOWEN SMITH BY M 5% ATTORNEY- FLOWCONTROL OF FLUIDIZED MATERIAL NATURE AND OBJECTS OF INVENTION Thisinvention relates to control of flow of fluidized material, i.e.,granular or pulverulent material entrained in a gas and conveyed underpressure in a conduit such as a pipe or hose. The apparatus to controlthe flow of fluidized material may constitute a part of a system forrockdusting for use in mines.

The primary object of the invention is to control the flow of fluidizedmaterial to maintain the proper ratio of solid material and gas undervarying conditions of restricted flow, and to start and cutoff dischargeof the material with automatic cessation and resumption of flow ofmaterial through the conduit. In the application to a system ofrockdusting, the discharge of material at the nozzle may be restrictedor stopped, and flow of material and gas in proper proportions will beautomatically restricted or resumed in response to the operation at thenozzle.

The flow of fluidized material is controlled by pressure developed inthe conduit. An increase in pressure restricts the flow of material inthe conduit and at the same time, increases the supply of gas tomaintain the proper ratio of gas to solid material with elimination ofclogging and blocking of the conduit. The pressure in the material flowconduit acts on two valves, one in the material flow control conduit andone in a gas supply conduit connected to the material flow conduit,causing the first valve to decrease flow of the fluidized material andthe second to increase the supply of gas. An increase in density ofmaterial, by increasing the pressure, thereby causes more gas and lessmaterial to be injected into the material flow conduit and flow of thematerial continues freely and smoothly.

This operation is especially adaptable to a rockdusting system. A tankof fluidized rockdust material may be connected to the nozzle by a longhose, so that the rockdusting operation may be carried on at a distancefrom the tank. A valve in the nozzle is operated manually to start orstop the dusting operation. The flow control apparatus controls the flowof material and gas in response to operation of the valve, starting orstopping the flow of material as the valve is operated at the nozzle,and adjusting the flow with change in the rate of discharge of therockdust material.

DRAWINGS In the drawings:

FIG. 1 is a diagrammatic view of a rockdusting system which incorporatesthe material flow control apparatus.

FlG. 2 is a side elevation of the nozzle and discharge valve.

FIG. 3 is an end elevation ofthe nozzle of FIG. 2.

FIG. 4 is a vertical cross section of a gas flow control valve used inthe flow control apparatus.

FIG. 5 is an elevational view, with parts in vertical cross section, ofa material flow control valve used in the flow control apparatus.

GENERAL DESCRIPTION The low control apparatus of this invention is usedin conveying fluidized material and has special advantages whenincorporated in a rockdusting system, as illustrated diagrammatically inFigure l. The rockdust material is fluidized in the closed container ortank 10, conveyed by conduit 12 from the container under control of theflow control apparatus to a nozzle 30, and discharged upon actuation ofamanually actuated valve in the nozzle. Flow of the fluidized material isregulated automatically by the flow control apparatus 20, in which apressure actuated gas flow control valve 50 controls the supply of gasto the fluidized material in the material flow conduit 12, and apressure actuated material flow control valve 60 controls the flow ofmaterial in the material flow conduit.

The rockdust container 10 may be of the type shown in applicants US.Pat. No. 3,356,264 and 3,393,832, but is shown here in diagrammatic formwith a pervious bottom wall 16 spaced above the bottom 15 of the closedcontainer to form an airspace 17. Gas supplied by a compressor 11 to thespace 17 passes upwardly through the rockdust material which isfluidized and discharged through the outlet 18 and conveyed by materialflow conduit 12 to nozzle 30. Conduit 12 may be closed by manual valve21.

The end of conduit 12 is formed as a hose connected to a fitting 31 onthe nozzle 30. To the other end of fitting 31, a flexible tubular member32 is secured by a collar 33 integral with the circular nozzle body 34,which receives the outer end of the flexible tubular member 32. Atransverse member 35 is fixed across the mouth of the nozzle 34 belowsaid flexible member and a complementary movable transverse member 36 isslidably mounted above the flexible member, so that when the member 36is moved toward the lower member 35, the tubular member 32 is flattenedto restrict the discharge opening, while forming an elongated outlet foremission of rockdust material. The member 36 is moved radially by athreaded shaft 37 journaled to the movable member 36 and threaded into aplate 38 carried by the nozzle body 34. A handwheel 39 on the end ofshaft 37 rotates the shaft and moves the member 36 to adjust the openingin the tubular member 32.

The pressure actuated material flow control valve 60 to control flow offluidized material through the conduit 12 is a standard valve of the6300 series manufactured by the Flexible Valve Corporation. The valve,casing 61 contains flexible tubular valve body 62 and is formed with atransverse bridge 63 supporting the center of the tubular body 62. Atransverse bar 64 fixed on the end of an operating stem 65 is movabletoward bridge 63 to close the flexible tubular body 62. A fluid motor ina pressure casing 66 fixed to valve casing 61 comprises a diaphragm 67separating the pressure casing into two chambers 70 and 71. Operatingstem 65 extends through bushing 69 into pressure casing 66 with its endfixed to plates 68 of diaphragm 67. Gas may be supplied under pressureto chambers 70 and 71 through connections 72 and 73 to operate thediaphragm to close and open valve 60.

Downstream from the material flow control valve 60 in the material flowconduit 12, a gas supply conduit 51 connects to the material flowconduit 12 to inject gas into the fluidized material. This gas conduit51 connects to the top of the material container 10 above the level ofthe material to receive gas under pressure from the container. The gasconduit may be closed by manually operated valve 22, and the passage ofgas is controlled by the pressure actuated gas flow control valve 50.The valve 50 is a standard Grinnell valve, having a diaphragm 52 carriedby stem 53 to close the passage between ports 54 55. The casing 56contains the fluid motor comprising a diaphragm 57 which is fixed to thevalve stem 53 and which divides casing 56 into two chambers 58, 59 sothat pressure on the diaphragm 57 may open and close valve 50. Gasconduit 51 may be closed by manual valve 22.

The material flow control valve 60 and gas rlow control valve 50 areactuated by gas pressure to open and restrict the material flow conduit12 and the gas conduit 51. A pipe from the gas compressor 11 has apressure regulator valve 81 which provides constant pressure in theline. The valve 81 is a standard adjustable pressure regulator valve.one example of which is known as Wilkerson regulator Model 2001 seriesB. Gauges 82 and 83 in the line 80 above and below the regulatorregister the pressure in the line and provide for adjustment of thepressure by valve 81. A filter 84 in the line prevents dust orextraneous matter reaching the regulator valve 81 or the fluid motors ofvalves 50 and 60.

The line 80 provides a source of constant pressure to the fluid motorsof the control valves. This line leads to the chamber 70 of the fluidmotor of valve 60 and acts on the diaphragm 67 to open the valve. Theline 80 also leads to chamber 58 of the fluid motor of gas flow controlvalve 50 and acts on the diaphragm 57 to close the gas control valve 50.

The operation of valves 50 and 60 is further controlled by pressure inthe material flow conduit 12 below the valve 60 through a pipe 90connected to the conduit 12 at a point downstream from valve 60. Thispipe connects to chamber 71 of the fluid motor of valve 60 to act toclose the valve in opposition to the constant pressure in pipe 80. Thepipe 90 also connects to chamber 59 of the fluid motor of valve 50 sothat the pressure acts on diaphragm to open the valve against theconstant pressure. An increase in pressure in the material flow conduit12 will increase the restriction of valve 60 and decrease the flow offluidized material, and will decrease the restriction of the gas flowcontrol valve 50 and increase the gas supply to the conduit 12. A filter91 in the pipe 90 prevents passage of dust from the conduit 12 to thefluid motors. A gauge 92 registers the pressure in the pipe 90.

in operation of the rockdusting system, valves 21 and 22 in the materialflow conduit 12 and gas conduit 51 are first closed, and compressor 11is operated to compress gas, usually air, in the container 10. Thepressure regulator valve 81 is set at the pressure desired in the lineand, when valves 21 and 22 are opened, the system is ready foroperation.

The valve in nozzle 30 is open to discharge the material at the raterequired for the dusting operation, the reduced pressure causing valve60 to open and valve 50 to close partially, as determined by thepressure in the conduit 12 resulting from the valve in nozzle 30. Thefluid motors of these valves will hold the valves in a state ofequilibrium between the constant pressure of line 80 and pressure inconduit 12. The rockdusting operation may be stopped by closing thevalve in the nozzle, and commenced at any time merely by opening thevalve, so that one man at the nozzle has complete control of the entireapparatus.

This control of the flow assures sufficient gas in the fluidizedmaterial to prevent clogging and maintaining a proper ratio of gas tomaterial. The efficiency of the rockdusting operation is improved andthe danger caused by bucking" of the hose from improper mixture ofmaterial and gas is avoided.

When the pressure regulator 81 is set for a given fluid pressure, anyincrease in pressure in the material flow conduit 12 in excess of thatfor which the regulator is proportioned, will open the gas flow controlvalve material and farther to supply more gas to the fluidized materialin conduit 12, and material valve 60 will close partially until thepressure in conduit 12 is approximately that of the proportioned ratioof pressure in fluid supply pipe 80. At the same time, the material flowcontrol valve 60 may also increase its restriction to flow in conduit12, an action which will decrease the pressure in the conduit. The flowcontrol apparatus will maintain a pressure in the material flow conduit12 as determined by the setting of pressure regulator, by control ofthesupply of gas or the combined action of both controls. When a uniformmixture of material and gas is required under different operatingconditions, this combined action is especially effective.

While especially exemplified in the rockdusting system, the flow controlapparatus may be used to regulate the flow in any fluidized conveyingsystem. With this control, flow of the material may be started andstopped at a distance, blockage of the material is avoided and uniformflow can be maintained.

What I claim is:

1. In a fluidized material conveying system, a material flow conduit forconveying said fluidized material, an adjustable discharge valve forsaid conduit to control discharge of material from said conduit, andmeans to supply gas to said fluidized material to prevent clogging whensaid discharge valve restricts passage of said material, comprising agas conduit for supplying gas to said to said fluidized materialconnected to said material flow conduit, a pressure actuated gasflowcontrol valve in said gas conduit, and means to adjust said pressureactuated valve to increase the flow of gas in said gas conduit inresponse to increase of pressure in said material flow conduit, whichresults from an increase in material in said material flow conduit orfrom closure ofsaid discharge valve.

2. In a fluidized material conveying system, a material flow conduit forconveying said fluidized material, adjustable material flow controlmeans to control flow of fluidized material in said material flowconduit, a gas supply conduit connected to said material flow conduitdownstream from said material flow control means to supply gas to saidfluidized material, adjustable flow control means to restrict flow ofgas in said gas supply conduit, and means to adjus said two flow controlmeans in response to variations in pressure in said material flowconduit downstream from said material flow control means.

3. In a fluidized material conveying system, a material flow conduit forconveying said fluidized material, a discharge valve for said conduit tocontrol discharge of material from said conduit, a pressure actuatedadjustable material flow control valve in said conduit upstream fromsaid discharge valve, means to supply gas to said fluidized material toprevent clogging when said discharge valve restricts passage of saidmaterial, comprising a gas conduit for supplying gas to said fluidizedmaterial connected to said material flow conduit between said valves,and a pressure actuated gas flow control valve in said gas conduit, andmeans to adjust said pressure actuated valves to control the flow ofmaterial in said material flow conduit and the flow of gas in in saidgas conduit under control of the pressure in said material flow conduitbetween said two valves in said material flow conduit so that saidmaterial does not clog said conduit and that sufficient gas to materialratio is supplied to maintain flow of material.

4. In a fluidized material conveying system, a material flow conduit forconveying said fluidized material, adjustable material flow controlmeans to restrict flow of fluidized material in said material flowconduit, a gas supply conduit connected to said material flow conduitdownstream from said material flow control means to supply gas to saidfluidized material, adjustable gas flow control means to control flow ofgas in said gas supply conduit, and means operated by pressure in saidmaterial flow conduit downstream from said material flow control meansto actuate said adjustable gas flow control means to control the flow ofgas to said material flow control conduit, so that increase of pressurein said conduit increases the ratio of gas to material in said materialflow conduit.

5. In a rockdusting system, a reservoir including means to admit gas tofluidize rockdust material in said reservoir, a source of gas underpressure connected to said reservoir to fluidize the material therein, amaterial flow conduit leading from said reservoir to convey fluidizedmaterial, an adjustable valve on the end of said conduit to control thedischarge of material from said conduit, a gas conduit for gas from saidsource and connected to said material flow conduit for supplying gas tosaid fluidized material in said material flow conduit, a pressureactuated material flow control valve in said material flow conduitbetween said reservoir and the connection of said gas conduit forcontrolling flow of fluidized material, a pressure actuated gas flowcontrol valve in said gas conduit for controlling the gas supply to saidmaterial flow conduit, means connecting a source of gas under pressureand said material flow conduit beyond said gas conduit to said pressureactuated valves, so that an increase in pressure in said material flowconduit causes the material pressure actuated control valve to restrictflow of material and decrease the pressure in the material flow conduitbeyond said first valve and also causes the second valve to open so thatmore gas is admitted '0 the material flow conduit to reduce the pressurein said material flow conduit.

6. The method of controlling the flow of fluidized material under fluidpressure through a material flow conduit comprising supplying fluid tosaid fluidized material at a point in said conduit, applying thedifference in pressure between a constant fluid pressure source and thepressure in said conduit downstream from said point to control the fluidsupplied to said conduit so that the ratio of fluid to material isincreased with increase in pressure in said conduit.

7. The method of conveying fluidized material through a material flowconduit under pressure, comprising applying gas under pressure tomaterial to be conveyed to fluidize said material and to convey saidmaterial in said conduit, applying the difference in pressure between aconstant pressure source and the pressure in said conduit to restrictpassage of said fluidized material in said conduit, supplying gas tosaid conduit downstream from the restriction in said passage andapplying said difference in pressure to control the gas supplied to saidconduit so that the ratio of gas to material is increased with increasein pressure in said conduit.

8. The method of conveying fluidized material through a material flowconduit under pressure, comprising variably restricting the flow ofmaterial at a point in said conduit, supplying gas to said conduitdownstream from said point, variably restricting the flow of gas to saidconduit, and increasing the restriction of flow of said material anddecreasing the restriction of the flow of gas in response to increase inpressure in said conduit downstream from said point.

9. The method of rockdusting which comprises passing gas into a mass ofrockdusting material to fluidize said material under pressure, conveyingsaid fluidized material through a conduit to a nozzle for dischargingsaid material for rockdusting, restricting the discharge of saidmaterial through said nozzle according to requirements of the operation,restricting passage of said fluidized material through said conduit inresponse to the difference in pressure between a constant pressuresource and the pressure in said conduit between said nozzle and therestriction of the passage in said conduit, and supplying gas to saidconduit between said nozzle and said restriction of the passage inresponse to said difference in pressure, so that increase in pressure insaid conduit increases the ratio of gas to material in said conduit.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,599,32 Dated August 17, 1971 lnventofls) Carlowen Smith It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 2, line 52, after "54" insert a comma. Column 3,

line 42, after "valve" cancel "material and" and insert 50 line 69,before "fluidized" cancel "to said".

Signed and sealed this 24th day of October 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents 39M PO-IOSO (IO-69) USCOMM-DC GOING-P69 u 5 GOVERNMENTPRINTING OFFICE was D 366-35l

1. In a fluidized material conveying system, a material flow conduit forconveying said fluidized material, an adjustable discharge valve forsaid conduit to control discharge of material from said conduit, andmeans to supply gas to said fluidized material to prevent clogging whensaid discharge valve restricts passage of said material, comprising agas conduit for supplying gas to said to said fluidized materialconnected to said material flow conduit, a pressure actuated gas flowcontrol valve in said gas conduit, and means to adjust said pressureactuated valve to increase the flow of gas in said gas conduit inresponse to increase of pressure in said material flow conduit, whichresults from an increase in material in said material flow conduit orfrom closure of said discharge valve.
 2. In a fluidized materialconveying system, a material flow conduit for conveying said fluidizedmaterial, adjustable material flow control means to control flow offluidized material in said material flow conduit, a gas supply conduitconnected to said material flow conduit downstream from said materialflow control means to supply gas to said fluidized material, adjustableflow control means to restrict flow of gas in said gas supply conduit,and means to adjust said two flow control means in response tovariations in pressure in said material flow conduit downstream fromsaid material flow control means.
 3. In a fluidized material conveyingsystem, a material flow conduit for conveying said fluidized material, adischarge valve for said conduit to control discharge of material fromsaid conduit, a pressure actuated adjustable material flow control valvein said conduit upstream from said discharge valve, means to supply gasto said fluidized material to prevent clogging when said discharge valverestricts passage of said material, comprising a gas conduit forsupplying gas to said fluidized material connected to said material flowconduit between said valves, and a pressure actuated gas flow controlvalve in said gas conduit, and means to adjust said pressure actuatedvalves to control the flow of material in said material flow conduit andthe flow of gas in in said gas conduit under control of the pressure insaid material flow conduit between said two valves in said material flowconduit so that said material does not clog said conduit and thatsufficient gas to material ratio is supplied to maintain flow ofmaterial.
 4. In a fluidized material conveying system, a material flowconduit for conveying said fluidized material, adjustable material flowcontrol means to restrict flow of fluidized material in said materialflow conduit, a gas supply conduit connected to said material flowconduit downstream from said material flow control means to supply gasto said fluidized material, adjustable gas flow control means to controlflow of gas in said gas supply conduit, and means operated by pressurein said material flow conduit downstream from said material flow controlmeans to actuate said adjustable gas flow control means to control theflow of gas to said material flow control conduit, so that increase ofpressure in said conduit increases the ratio of gaS to material in saidmaterial flow conduit.
 5. In a rockdusting system, a reservoir includingmeans to admit gas to fluidize rockdust material in said reservoir, asource of gas under pressure connected to said reservoir to fluidize thematerial therein, a material flow conduit leading from said reservoir toconvey fluidized material, an adjustable valve on the end of saidconduit to control the discharge of material from said conduit, a gasconduit for gas from said source and connected to said material flowconduit for supplying gas to said fluidized material in said materialflow conduit, a pressure actuated material flow control valve in saidmaterial flow conduit between said reservoir and the connection of saidgas conduit for controlling flow of fluidized material, a pressureactuated gas flow control valve in said gas conduit for controlling thegas supply to said material flow conduit, means connecting a source ofgas under pressure and said material flow conduit beyond said gasconduit to said pressure actuated valves, so that an increase inpressure in said material flow conduit causes the material pressureactuated control valve to restrict flow of material and decrease thepressure in the material flow conduit beyond said first valve and alsocauses the second valve to open so that more gas is admitted to thematerial flow conduit to reduce the pressure in said material flowconduit.
 6. The method of controlling the flow of fluidized materialunder fluid pressure through a material flow conduit comprisingsupplying fluid to said fluidized material at a point in said conduit,applying the difference in pressure between a constant fluid pressuresource and the pressure in said conduit downstream from said point tocontrol the fluid supplied to said conduit so that the ratio of fluid tomaterial is increased with increase in pressure in said conduit.
 7. Themethod of conveying fluidized material through a material flow conduitunder pressure, comprising applying gas under pressure to material to beconveyed to fluidize said material and to convey said material in saidconduit, applying the difference in pressure between a constant pressuresource and the pressure in said conduit to restrict passage of saidfluidized material in said conduit, supplying gas to said conduitdownstream from the restriction in said passage and applying saiddifference in pressure to control the gas supplied to said conduit sothat the ratio of gas to material is increased with increase in pressurein said conduit.
 8. The method of conveying fluidized material through amaterial flow conduit under pressure, comprising variably restrictingthe flow of material at a point in said conduit, supplying gas to saidconduit downstream from said point, variably restricting the flow of gasto said conduit, and increasing the restriction of flow of said materialand decreasing the restriction of the flow of gas in response toincrease in pressure in said conduit downstream from said point.
 9. Themethod of rockdusting which comprises passing gas into a mass ofrockdusting material to fluidize said material under pressure, conveyingsaid fluidized material through a conduit to a nozzle for dischargingsaid material for rockdusting, restricting the discharge of saidmaterial through said nozzle according to requirements of the operation,restricting passage of said fluidized material through said conduit inresponse to the difference in pressure between a constant pressuresource and the pressure in said conduit between said nozzle and therestriction of the passage in said conduit, and supplying gas to saidconduit between said nozzle and said restriction of the passage inresponse to said difference in pressure, so that increase in pressure insaid conduit increases the ratio of gas to material in said conduit.